MultiValuedMap instead
@Deprecated public interface MultiMap<K,V> extends IterableMap<K ,Object >
A MultiMap is a Map with slightly different semantics. Putting a value into the map will add the value to a Collection at that key. Getting a value will return a Collection, holding all the values put to that key.
For example:
MultiMap mhm = new MultiValueMap(); mhm.put(key, "A"); mhm.put(key, "B"); mhm.put(key, "C"); Collection coll = (Collection) mhm.get(key);
coll will be a collection containing "A", "B", "C".
NOTE: Additional methods were added to this interface in Commons Collections 3.1. These were added solely for documentation purposes and do not change the interface as they were defined in the superinterface Map anyway.
| Modifier and Type | Method and Description |
|---|---|
boolean |
containsValue(Object
Deprecated.
Checks whether the map contains the value specified.
|
Object |
get(Object
Deprecated.
Gets the collection of values associated with the specified key.
|
Object |
put(K key, Object
Deprecated.
Adds the value to the collection associated with the specified key.
|
Object |
remove(Object
Deprecated.
Removes all values associated with the specified key.
|
boolean |
removeMapping(K key, V item)
Deprecated.
Removes a specific value from map.
|
int |
size()
Deprecated.
Gets the number of keys in this map.
|
Collection |
values()
Deprecated.
Gets a collection containing all the values in the map.
|
clear, compute, computeIfAbsent, computeIfPresent, containsKey, entrySet, equals, forEach, getOrDefault, hashCode, isEmpty, keySet, merge, putAll, putIfAbsent, remove, replace, replace, replaceAllmapIteratorcontainsKey, entrySet, isEmpty, keySetboolean removeMapping(K key, V item)
The item is removed from the collection mapped to the specified key. Other values attached to that key are unaffected.
If the last value for a key is removed, implementations typically return null from a subsequent get(Object), however they may choose to return an empty collection.
key - the key to remove from
item - the item to remove
true if the mapping was removed,
false otherwise
UnsupportedOperationException - if the map is unmodifiable
ClassCastException - if the key or value is of an invalid type
NullPointerException - if the key or value is null and null is invalid
int size()
Implementations typically return only the count of keys in the map This cannot be mandated due to backwards compatibility of this interface.
Objectget(Object key)
The returned value will implement Collection. Implementations are free to declare that they return Collection subclasses such as List or Set.
Implementations typically return null if no values have been mapped to the key, however the implementation may choose to return an empty collection.
Implementations may choose to return a clone of the internal collection.
get in interface
Get<K,Object>
get in interface
Map<K,Object>
key - the key to retrieve
Collection of values, implementations should return
null for no mapping, but may return an empty collection
ClassCastException - if the key is of an invalid type
NullPointerException - if the key is null and null keys are invalid
Map.get(Object)
boolean containsValue(Objectvalue)
Implementations typically check all collections against all keys for the value. This cannot be mandated due to backwards compatibility of this interface.
containsValue in interface
Get<K,Object>
containsValue in interface
Map<K,Object>
value - the value to search for
ClassCastException - if the value is of an invalid type
NullPointerException - if the value is null and null value are invalid
Map.containsValue(Object)
Objectput(K key, Object value)
Unlike a normal Map the previous value is not replaced. Instead the new value is added to the collection stored against the key. The collection may be a List, Set or other collection dependent on implementation.
put in interface
Map<K,Object>
put in interface
Put<K,Object>
key - the key to store against
value - the value to add to the collection at the key
UnsupportedOperationException - if the map is unmodifiable
ClassCastException - if the key or value is of an invalid type
NullPointerException - if the key or value is null and null is invalid
IllegalArgumentException - if the key or value is invalid
Map.put(Object, Object)
Objectremove(Object key)
Implementations typically return null from a subsequent get(Object), however they may choose to return an empty collection.
remove in interface
Get<K,Object>
remove in interface
Map<K,Object>
key - the key to remove values from
Collection of values removed, implementations should return
null for no mapping found, but may return an empty collection
UnsupportedOperationException - if the map is unmodifiable
ClassCastException - if the key is of an invalid type
NullPointerException - if the key is null and null keys are invalid
Map.remove(Object)
Collection<Object > values()
Implementations typically return a collection containing the combination of values from all keys. This cannot be mandated due to backwards compatibility of this interface.